log4cxx-使用多个logger「建议收藏」

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转载自:http://blog.csdn.net/crazyhacking/article/details/9668267

使用多个logger时，所有logger的配置写在一个配置文件里面

两个例子：

1 一个继承的例子（http://logging.apache.org/log4cxx/）

//  file com/foo/bar.h
#include "log4cxx/logger.h"

namespace com {
   namespace foo {
      class Bar {
          static log4cxx::LoggerPtr logger;
          
      public:
          void doIt();
       }
    }
}

// file bar.cpp
#include "com/foo/bar.h"

using namespace com::foo;
using namespace log4cxx;

LoggerPtr Bar::logger(Logger::getLogger("com.foo.bar"));

void Bar::doIt() {
   LOG4CXX_DEBUG(logger, "Did it again!")
}

log4j.rootLogger=DEBUG, A1
log4j.appender.A1=org.apache.log4j.ConsoleAppender
log4j.appender.A1.layout=org.apache.log4j.PatternLayout

# Print the date in ISO 8601 format
log4j.appender.A1.layout.ConversionPattern=%d [%t] %-5p %c - %m%n

# Print only messages of level WARN or above in the package com.foo.
log4j.logger.com.foo=WARN

// file MyApp2.cpp

#include "com/foo/bar.h"
using namespace com::foo;

// include log4cxx header files.
#include "log4cxx/logger.h"
#include "log4cxx/basicconfigurator.h"
#include "log4cxx/propertyconfigurator.h"
#include "log4cxx/helpers/exception.h"

using namespace log4cxx;
using namespace log4cxx::helpers;
// Define a static logger variable so that it references the
// Logger instance named "MyApp".
LoggerPtr logger(Logger::getLogger("MyApp"));

int main(int argc, char **argv)
{
        int result = EXIT_SUCCESS;
        try
        {
                if (argc > 1)
                {
                        // BasicConfigurator replaced with PropertyConfigurator.
                        PropertyConfigurator::configure(argv[1]);
                }
                else
                {
                        BasicConfigurator::configure();
                }

                LOG4CXX_INFO(logger, "Entering application.")
                Bar bar
                bar.doIt();
                LOG4CXX_INFO(logger, "Exiting application.")
        }
        catch(Exception&)
        {
                result = EXIT_FAILURE;
        }

        return result;
}

The output of MyApp configured with this file is shown below.

2000-09-07 14:07:41,508 [12345] INFO  MyApp - Entering application.
2000-09-07 14:07:41,529 [12345] INFO  MyApp - Exiting application.

2 使用多个logger

前置知识

log4cxx可以使用配置文件进行设置，并且其设置方式与log4j兼容；
log4cxx库对日志流设置，只需更改配置文件中的appender属性；
log4cxx支持Logger继承机制，默认会继承父Logger的appender，由于要将日志流输出到多个文件中，因此需要将子Logger的继承属性设置为false.

配置子Logger

为了最大程度的灵活性，log4cxx引入了子Logger这个概念，即拥有与父Logger不同的行为，和编程语言中的OOP概念一致。

下面是在配置文件中定义一个子Logger的代码，其中ap0是logger0使用的appender：

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log4j.logger.logger0 = TRACE, ap0

设置子Logger不继承父Logger的appender：

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log4j.additivity.logger0=false

设置
子Logger所使用的日志文件，下述代码将
logger0的日志文件设定为当前程序目录下的
0.log：

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log4j.appender.ap0.File=./0.log

在程序中获取子Logger实例

首先是加载配置文件：

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log4cxx::PropertyConfigurator::configure(配置文件名称);

获取
子Logger实例：

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log4cxx::LoggerPtr logger = log4cxx::Logger::getLogger(子Logger名[例如上文中的”logger0″]);

FreeJudger项目中使用的完整配置文件

下述代码配置了8个
子Logger，用于
FreeJudger项目中判题线程的日志：

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log4j.additivity.gather = false

log4j.rootLogger=TRACE



log4j.logger.logger0 = TRACE, ap0

log4j.logger.logger1 = TRACE, ap1

log4j.logger.logger2 = TRACE, ap2

log4j.logger.logger3 = TRACE, ap3

log4j.logger.logger4 = TRACE, ap4

log4j.logger.logger5 = TRACE, ap5

log4j.logger.logger6 = TRACE, ap6

log4j.logger.logger7 = TRACE, ap7

log4j.logger.logger8 = TRACE, ap8



log4j.additivity.logger0=false

log4j.additivity.logger1=false

log4j.additivity.logger2=false

log4j.additivity.logger3=false

log4j.additivity.logger4=false

log4j.additivity.logger5=false

log4j.additivity.logger6=false

log4j.additivity.logger7=false

log4j.additivity.logger8=false



log4j.appender.logfile.encoding=UTF-8



log4j.appender.stdout=org.apache.log4j.ConsoleAppender

log4j.appender.stdout.layout=org.apache.log4j.PatternLayout

log4j.appender.stdout.layout.ConversionPattern=%5p [%t] (%F:%L) – %m%n



log4j.appender.R.MaxFileSize=100KB



log4j.appender.ap0=org.apache.log4j.RollingFileAppender

log4j.appender.ap0.ImmediateFlush=true

log4j.appender.ap0.File=./0.log

log4j.appender.ap0.MaxBackupIndex=10

log4j.appender.ap0.layout=org.apache.log4j.PatternLayout

log4j.appender.ap0.layout.ConversionPattern=%5p %d{HH:mm:ss} — %m%n



log4j.appender.ap1=org.apache.log4j.RollingFileAppender

log4j.appender.ap1.ImmediateFlush=true

log4j.appender.ap1.File=./1.log

log4j.appender.ap1.MaxBackupIndex=10

log4j.appender.ap1.layout=org.apache.log4j.PatternLayout

log4j.appender.ap1.layout.ConversionPattern=%5p %d{HH:mm:ss} — %m%n



log4j.appender.ap2=org.apache.log4j.RollingFileAppender

log4j.appender.ap2.ImmediateFlush=true

log4j.appender.ap2.File=./2.log

log4j.appender.ap2.MaxBackupIndex=10

log4j.appender.ap2.layout=org.apache.log4j.PatternLayout

log4j.appender.ap2.layout.ConversionPattern=%5p %d{HH:mm:ss} — %m%n



log4j.appender.ap3=org.apache.log4j.RollingFileAppender

log4j.appender.ap3.ImmediateFlush=true

log4j.appender.ap3.File=./3.log

log4j.appender.ap3.MaxBackupIndex=10

log4j.appender.ap3.layout=org.apache.log4j.PatternLayout

log4j.appender.ap3.layout.ConversionPattern=%5p %d{HH:mm:ss} — %m%n



log4j.appender.ap4=org.apache.log4j.RollingFileAppender

log4j.appender.ap4.ImmediateFlush=true

log4j.appender.ap4.File=./4.log

log4j.appender.ap4.MaxBackupIndex=10

log4j.appender.ap4.layout=org.apache.log4j.PatternLayout

log4j.appender.ap4.layout.ConversionPattern=%5p %d{HH:mm:ss} — %m%n



log4j.appender.ap5=org.apache.log4j.RollingFileAppender

log4j.appender.ap5.ImmediateFlush=true

log4j.appender.ap5.File=./5.log

log4j.appender.ap5.MaxBackupIndex=10

log4j.appender.ap5.layout=org.apache.log4j.PatternLayout

log4j.appender.ap5.layout.ConversionPattern=%5p %d{HH:mm:ss} — %m%n



log4j.appender.ap6=org.apache.log4j.RollingFileAppender

log4j.appender.ap6.ImmediateFlush=true

log4j.appender.ap6.File=./6.log

log4j.appender.ap6.MaxBackupIndex=10

log4j.appender.ap6.layout=org.apache.log4j.PatternLayout

log4j.appender.ap6.layout.ConversionPattern=%5p %d{HH:mm:ss} — %m%n



log4j.appender.ap7=org.apache.log4j.RollingFileAppender

log4j.appender.ap7.ImmediateFlush=true

log4j.appender.ap7.File=./7.log

log4j.appender.ap7.MaxBackupIndex=10

log4j.appender.ap7.layout=org.apache.log4j.PatternLayout

log4j.appender.ap7.layout.ConversionPattern=%5p %d{HH:mm:ss} — %m%n



log4j.appender.ap8=org.apache.log4j.RollingFileAppender

log4j.appender.ap8.ImmediateFlush=true

log4j.appender.ap8.File=./8.log

log4j.appender.ap8.MaxBackupIndex=10

log4j.appender.ap8.layout=org.apache.log4j.PatternLayout

log4j.appender.ap8.layout.ConversionPattern=%5p %d{HH:mm:ss} — %m%n